A tracking circuit is used in a memory circuit, such as a static random access memory (SRAM), to track timing of various signals of the memory circuit. In an existing approach, a tracking circuit includes a tracking bit line and a number of pull-down cells. When the tracking circuit is in operation, the pull-down cells pull down a voltage level on the tracking bit line. When the number of pull-down cells in the tracking circuit is large, the tracking bit line is affected by an electron migration phenomenon.
Like reference symbols in the various drawings indicate like elements.